I would not suggest for those concerned with such attacks to drop their guard, but I think that the most damaging manipulation of the power supply could be conducted in a far more subtle way.

1. Risk, a measure of whether or not our critical infrastructure is in fact vulnerable to this kind of event, and
2. Likelihood, a measure of whether or not those currently holding (or about to hold) this capability will use it.

According to your responses, it appears that you are saying that EMP is low risk, low likelihood. Is that correct?

Here.

Contrary to media reports, it is not true that an EMP attack from a typical strategic weapon would completely shut down the electronics within a country. First, the effect is statistical in nature – some systems will not notice the pulse at all while identical counterparts will be affected. Second, the most likely effect from an EMP attack is “upset” rather than destruction, that is, a temporary scrambling of the memory of a computer or the frequency of a communication device, something that is easily corrected by rebooting or resetting the device. (Upset can, however, have catastrophic consequences if the computer is the flight controller of an aircraft or another time-critical system.) Third, the EMP output from a typical device is degraded by several design isues so that few, if any, weapons currently deployed in military stockpiles will produce the maximum possible effect. Of all the nuclear effects, EMP seems the most prone to misunderstanding and misinterpretation.

With this in mind, another point to be made is how could any country with an atom project, like Iran and North Korea, be assumed to have an EMP capability in absence of the fact that they don’t even have any aboveground testing shots? Or in Iran’s case, any test shots — fizzles included — at all.

Is that correct?

The link to the EMP commission material doesn’t make that great a case for it when one considers the sources. They comprise a narrow group who are from the fringes of the gov/national lab/private sector natsec infrastructure. Nevertheless, it’s a scab they’ve been picking at for years, one that’s one of the pet hobby horses of Roscoe Bartlett.

Are you saying you’ve made a non ad hominem case against the EMP thing? Because your second link looks like a case for it, and I googled “site:dickdestiny.com emp” and the only claim I found you making that wasn’t “supporters of this idea are generally crazy” (which I will grant you) was your own interpretation of physics: that the inverse-square law means the effect will die out. That’s not exactly cut-and-dried.

Electromagnetic pulse effect was observed during Starfish size Cold War test shots. That’s megaton range, not Hiroshima scale. So right now, the discussion is ludicrous in terms of real world threats unless you think a nuclear barrage, Cold War power style, is likely.

The second idiocy involved in this discussion is that no one will care if an atomic detonation over or on the US is aimed at creating a NOTIONAL EMP effect. The response will be a nuclear barrage which reduces the suspected enemy to radioactive sand. In other words, the US strategic response will be to make the rubble bounce worldwide.

If you’re an enemy with a few atomic bombs, are you going to waste one on an atmospheric shot, thinking it MIGHT destroy the US retaliatory capability (even though you have no empirical evidence that it will)?

No.

Only crazy and misinformed people think so.

So what if everyone in North Korea is entirely crazy? They also haven’t been able to quite duplicate a Hiroshima or Nagasaki level shot fifty years after the fact.

What about Iran? They’re not even there yet.

So the entire construct is irrational. Who has made you think this is an easy thing and why?

So now you know you’ve been misled. You’re next logical question should be: “Why have I been twisted around so by EMP crazies?” None of them discuss the fine details.